Mercedes-Benz's Concept S-Class Coupe employs LED lighting all around, but nowhere in more striking fashion than in the interior. Mercedes said the blue was chosen to convey a "sporty and modern" look.(Source: Mercedes-Benz)

I'm guessing that the practical barrier to home adoption of the features of LED lighting (dimming and color changes) is that people have moved from living in the moment with each other and long family dinners to snacks on the go and watching TV while they multi-task on their iPad. They're not willing to pay $60 for a "novelty" light. They'll probably succeed first in products like make-up mirrors that adjust for indoor incandescent / indoor fluorescent / outdoor sunlight color balance. A niche product that takes advantage of the technical opportunity.

I think one of the biggest drivers in cars might be that they don't need to design in accessability (not that car manufacturers have done much in that way in the recent past. backlighting with globes can be an expensive service issue. I've spent as much as $50 getting a 10c globe replaced because the labour is horrific. with LED's they should exceed the life of the vehicle. Also I'm not sure LED tail lights and indicators come out cheaper than their incandescent counterparts, but the savings in metalwork and no need for lenses will certainly put a dent in that additional cost. I am glad to see that some makers have finally realised they need diffusers.

DrQuine, thanks for your comprehensive explanation. I used to think that because carmakers tend to be cost conscious, they would be the last to embrace LEDs. But you made all the strong cases for the use LED lights in cars. Makes sense.

You did mention in your comment:

Maybe one benefit for home use [LED Lights] is the ability to dial-a-mood not only in brightness but also in color.

Actually, since the first time when I wrote an LED lighting stoy, I was convinced that would trigger the widespread usage. But so far, it hasn't happened...I wonder why.

Cars are early adopters for LED lighting because reliability is very important, the space to illuminate (inside) is relatively small, and LED lights are very compact. Also, the basic power system in a car is 12 volts DC which works well with LED lights. In contrast, home power is 120 volts AC which requires power conversion to run the lights. Finally, the car manufacturers have control of the environment. Home sales require persuading 100 million people (one by one) to switch from something that they've used for years. One persuaded car designer can create a change that impacts millions of users. As the track record is proven in cars, people may be prepared for LED use at home (if they're not burned by their early failure experiences with CFL bulbs). Maybe one benefit for home use is the ability to dial-a-mood not only in brightness but also in color.

I have noticed a sharp increase in LED lighting in cars recently. It's almost to the point where you can guess which cars in a line (I live in SoCal, so I get to examine long lines of cars a lot...) are new. I suspect that costs have dropped on them enough that they can be used this widely. The next step is to start seeing more innovative use of LED lighting in homes.